Familial Presentation of Monocular Elevation Deficiency Syndrome due to Hypoplasia, Absence of Superior Rectus

To report a new familial presentation of hypoplasia and absence of superior rectus in the form of unilateral monocular elevation deficiency Case report : A 7-year-old boy was referred to our center (Poostchi eye clinic) with a chief complaint of ocular misalignment in his right eye since birth. One of his siblings was a known case of unilateral monocular elevation deficiency and was operated previously. Other family members were normal. Ocular motility examinations revealed more than 60 prism diopters hypotropia of right eye in primary position associated with limitation of elevation in both abduction and adduction. No pattern (A, V, etc.) was detected. There was no sign of craniosynostosis by neurologic exams or by imagings. Unilateral monocular elevation deficiency was diagnosed. Under operation congenital absence of superior rectus was found while in her sister’s chart review, only congenital hypoplasia of superior rectus was reported. This is the first report of familial presentation of monocular elevation deficiency resulted from both hypoplasia and absence of superior rectus. This finding may suggest the possible role of a genetic mechanism to be responsible for this disorder.